ac·ti·nism /ˈæktəˌnɪzəm/
  光化度
  ac·ti·nism /ˈæktəˌnɪzəm/ 名詞
  光化力,射線化學
  Ac·tin·ism n.  The property of radiant energy (found chiefly in solar or electric light) by which chemical changes are produced, as in photography.
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  actinism
       n : the property of radiation that enables it to produce
           photochemical effects